1. Field of the Invention
This invention relates to locks and more particularly to a novel and highly effective portable door lock design, light weight and compact in construction and to a lock that is especially adapted to provide a portable auxiliary personal locking mechanism for a door.
2. Description of the Related Art
Portable locks of many designs are known, including portable door locks. A portable door lock is typically used in addition to existing built in door locking mechanisms, such as a handle lock and/or deadbolt, to lock and secure a door. For example, a traveler may wish to provide an additional personal security measure for locking a hotel or motel room door. Since the keys for these rooms are used by many people, there is always uncertainty regarding who may have keys to a room. Although many hotel or motel room doors may include a slide lock or chain lock in addition to the traditional dead bolt and handle lock, there is generally more comfort and peace of mind knowing that the door is also secured by an additional security device which is known to not have been compromised and which a potential criminal would not be aware of if attempting to enter the room.
However, prior portable door locks leave much to be desired, especially when used under the difficult circumstances frequently encountered by travelers. For example, a portable auxiliary door lock is described in U.S. Pat. No. 5,325,685. The door lock provides for a temporary attachment between the edge of an arcuately hinged door and the adjacent door jamb to secure the door when it is closed. One end of the bar is bent at a 90 degree angle to insert into the latch recess of the striker plate. The lock cylinder faces away from the knob assembly and an additional stop plate is used to retain the door. However, such locks require a key to lock and unlock the lock cylinder. This arrangement is dangerous. Should the key become misplaced after the lock is in place, a person could be trapped in the room in the event of a fire, for example. In addition, such a door lock is awkward to use, since it requires one hand to hold the bar, while sliding the lock cylinder and holding it snugly against the door and at the same time, inserting the key into the lock cylinder and turning it to the locked position.